The invention relates to an original conveying apparatus for copying machine, and more particularly, to such apparatus which may be used to convey an original in the form of either sheet or thick material for effecting an exposure process and including a thick material receptacle which integrally carries a sheet original drive.
An original from which a copy is to be produced in a copying machine may be a single sheet or a thick material such as book. In most copying machines of the prior art, an original which may be in the form of either sheet or thick material is placed on a common receptacle, formed by a transparent plate, and is held in place by an original retainer before the receptacle is driven toward an exposure position. In such an arrangement, the original receptacle undergoes a reciprocatory movement with respect to an exposure station defined by original scanning optics which is fixedly located within the copying machine. However, the original is scanned only during the forward stroke of the original receptacle, and hence the time required to complete its reverse or returning stroke is entirely wasteful, causing a reduction in the speed of copying operation.
While a copying machine is available which is originally designed for use with originals in the form of sheets alone, this type of copying machine must be modified to allow a copying operation of thick materials. However, a very complex operation is required when copying from a thick material.
To overcome these difficulties, various arrangements have been proposed. In one arrangement, there is provided a conveying unit associated with an original in the form of a sheet and which is separate from a conveying unit associated with a thick material. A movable mirror is disposed in an optical path which focusses an image so that the movement of the mirror is effective to establish selectively the optical paths which may be used with a single sheet or thick material. In another arrangement, means is provided which selectively couples drive means with either a sheet original conveying unit or a thick material receptacle which is integrally provided on the sheet conveying unit at a location adjacent thereto, thus permitting a copying operation from either sheet or thick material.
However, the former requires the provision of means which selectively changes the optical path for projection of an image while the latter involves a manual operation to move the thick material receptacle through a given distance from its home position to its start position in order to disengage the meshing engagement between a drive gear associated with a sheet original and another gear provided in the drive means mounted on the part of the copying machine whenever it is desired to copy from a thick material. In either instance, the operation is cumbersome.